Crossword clues for Canal into Lake Ontario. 5 letters:TRENTCanal into Lake Ontario.TRENT___ Canal (connector of lakes Ontario and Huron)WELLANDCanal between Lake Erie and Lake Ontario, 27½ miles.RIDEAUCanal or lake in OntarioWELLANDCanal linking Lakes Erie and OntarioSTLAWRENCE___ Seaway (series of channels, locks and canals between Montreal and Lake Ontario): 2 wds.